Atomically　precise　metal　nanoclusters　(NCs)　present　new　opportunities　for　creating　innovative　solar-powered　photoanodes　due　to　their　extraordinary　physicochemical　properties.　Nevertheless,　ultrasmall　metal　NCs　tend　to　aggregate　and　lack　active　sites　under　light　irradiation,　which　severely　limits　their　widespread　application.　We　have　developed　a　strategy　to　design　efficient　ternary　photoanodes　by　successively　modifying　AgAu　NCs　and　CoNi-LDH　on　BiVO4　substrates　using　versatile　impregnation　and　electrodeposition.　The　electronic　properties　of　AgAu　NCs　facilitate　the　rapid　transfer　of　photogenerated　carriers　on　BiVO4　and　CoNi-LDH.　Additionally,　ultrathin　CoNi-LDH　acts　as　a　hole-collecting　layer,　which　quickly　extracts　holes　to　the　electrode/electrolyte　interface.　The　synergistic　effect　and　the　matched　energy　levels　between　the　ternary　heterostructures　promote　the　OER　process,　which　significantly　improved　the　photoelectrochemical　(PEC)　water　oxidation　performance.　This　study　presents　a　new　idea　for　further　exploration　of　metal　nanocluster-based　PEC　systems.　©　2024　American　Chemical　Society.